Biometrical Letters Vol. 54(1), 2017, pp. 61-76
|
EVALUATION OF THE IMPACT OF FERTILIZERS AND SEED QUALITY ON WINTER WHEAT YIELD Marzena Iwańska1, Zbigniew Laudański2†, Tadeusz Oleksiak2 1Department of Experimental Design and Bioinformatics, Warsaw University of Life Science – SGGW; e– mail: m.iwanska123@gmail.com 2Plant Breeding and Acclimatization Institute – National Research Institute (IHAR-PIB), Radzików |
The aim of the study was to evaluate the effect of mineral fertilization and seed quality on the yield of winter wheat in production conditions. This assessment is made in terms of the expected probabilities of success in relation to the yield of analyzed cultivars, taking into account the interaction of the factors considered. Analyses were performed on data from 3815 fields. The impact of fertilizers and seed quality was evaluated using logistic regression. Grain yield was transformed into a binomial variable, where values were divided into two classes, i.e. below the mean and above the mean. The results of the analysis proved a significant effect of fertilization rate, which was modified by different seed quality. The highest probability of obtaining yields above the mean was observed for pre-basic and basic seed quality at high fertilizer rates.
logistic regression, odds ratio, survey research, winter wheat
